A wiring substrate is known, which is of the type adapted to mount thereon a semiconductor chip (see, for example, Patent Documents 1 and 2). In this type of wiring substrate, connection terminals are provided for connection to the semiconductor chip.
Patent Document 1 discloses to form an insulating layer with an opening through which a plurality of connection terminals are exposed, provide an insulating substance between the connection terminals within the opening, and then, perform plating on the connection terminals for the purpose of preventing an electrical short circuit caused between the connection terminals by plating material. Patent Document 2 discloses to, for the purpose of preventing an electrical short circuit caused between connection terminals by soldering, form an insulating layer between the connection terminals and make the thickness of the insulating layer smaller than that of the connection terminals.